Transcript Lecture 11 - cda college

LAN and WAN Design:
Putting It All Together
Chapter 11
Learning Objectives
Discuss general LAN and WAN design
issues that include using structured wiring
and structured networking
Describe and implement LAN design
principles
Explain and implement WAN design
principles
General LAN and WAN
Design Issues
Factors that affect design
Analyzing existing topology and resources
Network management
Cable installation and replacement
Structured wiring
Vertical wiring and structured networking
Full-duplex communications
Bridge, router, and hub design issues
Factors That Affect a LAN or
WAN Design
Anticipated network traffic
Redundancy requirements
User movement
Accommodating for future growth
Security considerations
WAN connectivity
LAN and WAN costs
Designing for Redundancy
Analyzing Existing Topology
and Resources
Inspect cable plant
Compile bandwidth utilization baseline data
Audit resources
Review traffic
Perform network capacity management
Network Management
Directly related to network design and
topology; some topologies are easier to
manage than others
Cable Installation and Replacement
Limitations of Thinnet/Thicknet
Cable Plants
Cannot meet high bandwidth requirements
Expensive to maintain and troubleshoot
Difficult to expand
Cable Replacement Factors
Replacement of legacy cable
Cable and connector costs
Installation costs
Environmental requirements
Extra cable requirements
Creation or redesign of wiring closet
locations
Guidelines for Installing Cable
Use structured wiring and structured networking
principles
Meet or exceed maximum bandwidth required
Install Category 5 or better UTP cable horizontally
to desktop
Install multimode fiber-optic riser cable between
floors
Follow IEEE specs for cable run distances
Single-mode fiber-optic cable for long runs
continued…
Guidelines for Installing Cable
Install 802.11 wireless options where
appropriate
Install star-based cable plants
Install only high-quality cable
Follow all building codes
Do not exceed 25 pounds of force when
pulling twisted-pair cable
Follow rules for cable bend radius
continued…
Guidelines for Installing Cable
Leave extra cable at endpoints
Use a qualified contractor, if desired
Adhere to IEEE specs for cable and
installation
Label cable following EIA/TIA-606
standard
Ground cable plants
Structured Wiring
Cable fans out in horizontal star fashion from
centralized chassis switch(es) or hub(s) located in
telecommunications rooms or wiring closets
Structured Wiring
Requirements
Flexible cabling, eg, twisted-pair
Wiring nodes into physical star
Adherence to EIA/TIA-568-A / EIA/TIA568-B standards for horizontal wiring
Centralized cable plant in chassis hubs or
switches
Built-in intelligence for chassis hubs or
switches
continued…
Structured Wiring
Requirements
Ability to isolate hosts/servers on own cable
segment
Ability to provide high-speed links to
network devices
Vertical Wiring
Cabling and network equipment used
between floors
Physically links telecommunications
room(s) on one floor to adjoining floors
Ties horizontal cable on each floor into
logical backbone
Principles of Vertical Wiring
Deploy extended star topology between devices
Use high-speed cable to reduce congestion and
because it is not susceptible to EMI and RFI
Follow EIA/TIA-568-A / EIA/TIA-568-B
standards for vertical or backbone cabling
Use riser rated cable for cable runs through cable
ports or vertical shafts
Install fire-stop material
Structured Networking
Use of solid horizontal and vertical wiring
design that enables centralizing a network at
strategic points
Administrative Capabilities of
Structured Networks
Centralize or distribute network
management
Incorporate vertical and horizontal network
design using high-speed communications on
the backbone (fat pipes)
Reconfigure network physically and
logically
continued…
Administrative Capabilities of
Structured Networks
Segment network according to workgroup
patterns, using VLANs
Add redundancy
Quickly expand network and introduce new
high-speed network options
Proactively monitor and diagnose problems
for quick resolution
Using Full-Duplex
Communications
Ability to send and receive simultaneously
Use in areas of network with high-speed links
Eliminates collisions
Increases network throughput and reduces number
of lost frames
Most switches employ one of two types of flow
control
Jamming
Buffering
Bridge, Router, and Hub
Design Issues
Bridges and routers
Design flexibility
High-speed networking options
Redundancy
Hubs
Centralize network management and
troubleshooting
Reproduce network traffic on all segments
Advantages of RFIs and RFPs
Help organizations clearly define needs
Provide vendors with understanding of the
organization
Enable vendors to show how they would
address those needs
Provide basis for contract negotiation
Supply guidelines for installation process
LAN Design Principles
Replace legacy hubs with switches
Replace older switches that do not offer SNMP
compatibility with newer ones that have it
Connect high-speed workstations to switches
Connect servers to high-speed switched ports
Connect integrated or workgroup area switches to
high-speed switches
Connect major department segments or high-speed
switches to routers
Walking Through a Design
Locating Hosts and Servers
In centralized host or server farms
Saves money
High traffic
In different locations throughout the network
Reduces network traffic
Provides security
Flexibility if disaster destroys one location
Can have redundant hosts at different locations
Connecting Hosts and Servers
Building in Redundancy
Interspersed Hosts and Servers
Designing for Multimedia
Applications
Often include increased bandwidth
Often include implementation of Internet
Group Management Protocol
Wireless LAN Network
Designs
Peer-to-peer
Multiple-cell
Peer-to-Peer Design
Maintenance and
Support Issues
Constant process
To reduce maintenance, develop schemes to
replace aging devices before they become a
maintenance problem
WAN Design Principles
Devices required at local site to accomplish WAN
connectivity
Routers
Access servers
Modems
Specialized adapters
Multiplexers
Wireless, microwave, and satellite devices
ATM WAN access switches
Configuring LAN Topology for
WAN Connectivity
WAN Connectivity Using a
Router
Wireless MANs and WANs
Wireless MAN options
Wireless bridge
Proprietary infrared design
Proprietary radio wave options
Terrestrial microwave
Wireless WAN options
Geosynchronous satellites
LEO satellites
WAN Provider Topologies
Established by WAN service provider
Selection depends on:
Bandwidth required
Budget
Speed and type of interfaces on the LAN
Price Structure
Ranges from unlimited usage to limited usage
billed per minute
Cost-related elements
Monthly service charges
LAN connectivity equipment
User training and support
Network staff training
Network support and troubleshooting
Lost work time when a connection is down
Periodic equipment upgrade costs
Bandwidth Considerations
Choice of service provider depends on:
Amount of bandwidth needed
Service level agreement (SLA) offered by
provider
Vendor and Customer
Equipment
Equipment varies according to size of
vendor
Equipment should be at more than one
location
Chapter Summary
General LAN design principles
Accommodating for growth and security
Implementing the cable plant
Using structured wiring and structured networking
techniques
Using full-duplex communications
Designing around switches and routers
Creating requests for information and requests for
proposals
continued…
Chapter Summary
Specific LAN design principles
Where to locate hosts and servers
How to design for multimedia applications
Wireless LAN designs and maintenance and
support issues
continued…
Chapter Summary
WAN design principles
Wireless MAN and WAN designs
WAN provider topologies
Price structure
Bandwidth
Equipment issues